If you have MS Office available, use Microsoft Picture manager to resize the image to 500kb or less.
1)Open the folder containing the image, right click and open with MS Office pict manager.
2)Click on edit pictures and on the right hand side use the compress function to make it smaller.
3)Check image is less than 800x800 in size
4)post it
For high res images hosted elsewhere online:
To post images inline use the url function else upload as attachments and select place inline.
see below